To an ever-increasing extent, houses, flats, home units and other buildings are being fitted with security grilles or panels over all or part of window and door openings so that ventilation is achieved and insects excluded by the provision of mesh, but without burglars or other intruders being able to enter. Such security panels may not be strictly necessary for some openings which are high or otherwise not easily accessible, but they are considered almost essential for window and door openings at lower levels such as ground or first floors. Unfortunately, the abovementioned benefits can be offset in the minds of ill, elderly disabled or feeble occupants by the disadvantage of knowing that the security panels also prevent escape in emergency circumstances such as in the event of a fire which might be so located as to prevent adults or children from reaching an "unbarred" access opening.